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Encyclopedia > Copy prevention

Copy prevention, also known as copy protection, is any technical measure designed to prevent duplication of information. Copy prevention is often hotly debated, and is sometimes thought to infringe on customers' property rights: for example, the right to make a backup copy of a videotape they have purchased, or to install and use computer software on multiple computers.

Contents


Introduction

From a technical standpoint, it would seem impossible to completely prevent all users from making copies of such media as CDs, DVDs, videotapes, computer software discs, or video game discs. The basic technical fact is that all these types of media require a "player"—a CD player, DVD player, videotape player, computer, or video game console, in these five examples. The player has to be able to read the media in order to display it to a human. In turn, then, logically, a player could be built that first reads the media, and then writes out an exact copy of what was read, whether to the same type of media that was read, or to some other format, such as a file on a hard disk. Size of CD compared to pencil. ... DVD is an optical disc storage media format that can be used for storing data, including movies with high video and sound quality. ... Bottom view of VHS videotape cassette with magnetic tape exposed Videotape is a means of recording television pictures and accompanying sound onto magnetic tape as opposed to movie film. ... Computer software (or simply software) refers to one or more computer programs held in the storage of a computer for some purpose. ... A computer game is a game composed of a computer-controlled virtual universe that players interact with in order to achieve a defined goal or set of goals. ... The Nintendo GameCube is an example of a video game console. ... Typical hard drives of the mid-1990s. ...


Copying of information goods which are downloaded (rather than embedded in physical media) can be restricted more effectively. They can be encrypted in a fashion which is unique for each user's computer, and the decryption system can be made tamper-resistant (see also traitor tracing). In the field of computer security, system hardware is said to be tamper-resistant if it is difficult to modify or subvert, even for an assailant who has physical access to the system. ... Traitor tracing is a copy prevention strategy which has been around for years. ...


At a minimum, digital copy prevention is subject to the analog hole: regardless of the digital restrictions, if music can be played on speakers, it can also be recorded. Copying text in this way is more tedious, but if it can be printed or displayed, it can also be scanned and OCRed. The analog hole refers to a fundamental vulnerability in copy prevention schemes for digital content which is intended to be played back using analog means. ... Wikibooks Wikiversity has more about this subject: School of Music Look up Music in Wiktionary, the free dictionary Wikicities has a wiki about Music: Music Music City : a collaborative music database All Music Guide: includes a comprehensive and flexible Genre and Style system MusicWiki: A Collaborative Music-related encyclopedia Science... Closeup of a loudspeaker driver A loudspeaker is a device which converts an electrical signal into sound. ... In language, text is a broad term for something that contains words to express something. ... Optical character recognition, usually abbreviated to OCR, involves computer systems designed to translate images of typewritten text (usually captured by a scanner) into machine-editable text—to translate pictures of characters into a standard encoding scheme representing them (ASCII or Unicode). ...


Since this basic technical fact exists, copy prevention is not intended to stop professional operations involved in the unauthorized mass duplication of media, but rather to stop casual copying in which one friend makes a copy of a disc for another friend and thus (arguably) decreases the possible market for that disc by one copy.


Note on terminology

Publishers who implement copy prevention have historically referred to the technology as copy protection as it carries the implication of preventing destruction or suffering. However, as the act of copying information does not necessarily result in destruction, suffering, or even loss of business profits, many people believe this term is misleading. Advocates of copyright reform and copyright abolishment in particular believe the term wrongly encourages people to identify with publishers who benefit from copy prevention rather than the users who are restricted by it. Copy prevention is a neutral term which simply describes the purpose of the technology without passing judgment on whether the act of copying is inherently damaging.


Copy prevention on various media

Copy prevention has been attempted in many ways, long before computers and digital media entered the picture. For example, the ancient practice of watermarking is an attempt to, if not prevent a copy, at least prove the authenticity of the original. The music industry in particular has long sought a reliable copy prevention method—early attempts included adding a high frequency spoiler signal to an analog recording so that tape recorders would generate an unpleasant whistle when the spoiler heterodyned with the bias oscillator. These attempts were largely unsuccessful since the spoiler was either audible to the listener, or else so high that it would not be reproduced reliably when played back. Videotape manufacturers had more success, with companies like Macrovision inventing clever schemes that would make copies unusable if they were created with a normal VCR, and licensing this technology to videotape manufacturers. This Crown & CA (for Crown Agent) watermark was standard for postage stamps of the British colonies from the 1880s to the 1920s. ... In general, a tape recorder, tape deck, cassette deck or tape machine is any device that records a fluctuating signal by moving a strip of magnetic tape across a tape head, which is a strong electromagnet. ... In telecommunications, to heterodyne is to generate new frequencies by mixing two or more signals in a nonlinear device such as a vacuum tube, transistor, or diode mixer. ... Bias has several different meanings, most relating to an offset or prejudice of some sort. ... Bottom view of VHS videotape cassette with magnetic tape exposed Videotape is a means of recording television pictures and accompanying sound onto magnetic tape as opposed to movie film. ... Macrovision is a company that creates electronic copy prevention schemes. ... The video cassette recorder (or VCR, less popularly video tape recorder) is a type of video tape recorder that uses removable cassettes containing magnetic tape to record audio and video from a television broadcast so it can be played back later. ...


Some modern forms of copy prevention are invisible to the end-user, such as CD subchannel data or other mechanisms such as SafeDisc which only become apparent once an attempt to copy is made. Size of CD compared to pencil. ... SafeDisc is a CD/DVD copy protection solution by Macrovision Corporation. ...


Copy prevention for computer software

Copy prevention for early home computer software, especially for games, started a long cat-and-mouse struggle between publishers and crackers. Programmers who as a hobby would defeat copy prevention on software often add their alias to the title screen, and then distribute the cracked product to the network of warez BBSes or Internet sites that specialized in distributing unauthorized copies of software. Software cracking is the modification of software to remove encoded copy prevention. ... Warez (pronounced wares) is a derivative for the plural form of the word software meaning copyrighted material traded in violation of its copyright license. ... A bulletin board system or BBS is a computer system running software that allows users to dial into the system over a phone line and, using a terminal program, perform functions such as downloading software and data, uploading data, playing games, reading news, and exchanging messages with other users. ...


Software copy prevention schemes for early computers such as the Apple II and Commodore 64 computers depended on precise knowledge of what exactly would happen if that hardware were forced to do something unusual, such as to read a disk sector that was unformatted, or to take just a few microseconds longer than necessary when instructing the floppy disk drive arm motor to move. This sort of physical copy prevention continues today on software shipped on CD-ROM, with companies like Macrovision and Sony providing copy prevention schemes that work by writing data to places on the CD-ROM where a CD-R drive cannot normally write. Such a scheme has beelllllllllllllllllllllllllllllllllllllInsert non-formatted text here The Apple II was one of the most popular personal computers of the 1980s. ... The Commodore 64 (C64, CBM 64) was a popular home computer of the 1980s. ... A floppy disk is a data storage device that is composed of a circular piece of thin, flexible (i. ... The CD-ROM (an abbreviation for Compact Disc Read-Only Memory (ROM)) is a non-volatile optical data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. ... Macrovision is a company that creates electronic copy prevention schemes. ... Sony Corporation (Japanese katakana: ソニー) (TYO: 6758), (NYSE: SNE) is a global consumer electronics corporation based in Tokyo, Japan. ... A CD-R (Compact Disc-Recordable) is a thin (1. ...


Link titlen used for the Sony PlayStation and cannot be circumvented easily without the use of a modchip. Part of the Style and how-to series Shortcut: WP:HEP See also Help:Editing, m:Help:Editing, m:Help:Starting_a_new_page Wikipedia is a WikiWiki, which means that anyone can easily edit any unprotected article and have those changes posted immediately to that page. ... The original PlayStation was produced in a light grey colour; the more recent PSOne redesign sports a smaller more rounded case. ... A modchip is a device used to play import, backup, or homebrew games and/or circumvent the digital rights management of many popular game consoles, including the Xbox and PlayStation. ...


For software publishers, a less expensive method of copy prevention is to write the software so that it requires some evidence from the user that they have actually purchased the software, usually by asking a question that only a user with a software manual could answer (for example, "What is the 4th word on the 6th line of page 37?"). This approach can be defeated by users who have the patience to copy the manual with a photocopier, and it also suffers from BTO vulnerability, so that once crackers circumvent the copy prevention on a piece of software, the resulting cracked product is more convenient than the original software, creating a disincentive to buying an original. As a result, user-interactive copy prevention of this kind has mostly disappeared. A small, much-used Xerox copier in a high school library. ... A BTO vulnerability is a flaw in a copy prevention system that makes a copy of the product where the system has been circumvented Better Than the Original (ie an official copy) in some way. ...


Other software copy prevention techniques include:

  • A dongle, a piece of hardware that must be plugged into the computer to run the software. This adds extra cost for the software publisher, so dongles are uncommon for games and are found mostly in high-end software packages costing several thousand dollars.
  • Registration key, one single registration key that is "hard-coded" into the program's source that is asked for when running the program.
  • Name & Serial, a name and serial number that is usually given to the user at the purchase of the software and is almost always required to install it. The serial number is generated based upon the name given.
  • Keyfile, which requires the user to have a keyfile in the same directory as the program is installed to run it.
  • Serial, the program has an algorithm that allows multiple serial numbers to be entered in. Usually asks for the serial at installation or while running the program.
  • Nag screens, annoying messages that appear during or at the start of the program telling the user to register the program.
  • Time limit, allows user to use the software for x number of days before they have to register the program.
  • Use limit, allows user to use the software for x number of times before they have to reigster the program.
  • Crippleware, some functions may be disabled until the user registers the program.
  • A phone activation code, which requires the user to call a number and register the product to receive a computer-specific serial number.
  • Internet product activation, which requires the user to connect to the Internet and type in a serial number so the software can "call home" and notify the manufacturer who has installed the software and where, and prevent other users from installing the software if they attempt to use the same serial number.

The two latter methods imply tying the software installation to a specific machine by noting some particular unique feature of the machine. Some machines have a serial number in ROM, while others do not, and so some other metric, such as the date and time (to the second) of initialisation of the hard disk can be used. On machines with Ethernet cards, the MAC address, which is unique and factory-assigned, is a popular surrogate for a machine serial number (however, this address is programmable on modern cards). The problem with these sorts of schemes are that they can cause problems for a validly licensed user who upgrades to a new machine or reinstalls the software having reinitialised the disk, though some Internet product activation products can allow replacement copies to be issued to registered users or multiple copies to the same licensee. Like other software, copy-prevention software not infrequently contains bugs, whose effect may be to deny access to validly licensed users. As with all similar schemes, they are often easy to crack, and the resulting cracked software is perceived as being more valuable than the uncracked version. In the computer industry, the word dongle was used for many years to primarily refer to a small hardware device that connects to a computer and acts as an authentication key for a particular piece of software. ... Crippleware is a controversial form of shareware. ... Product activation is a license validation procedure required by some computer software programs. ... A serial number is a unique number applied to a product example, as opposed to a model number or type number. ... Rom is also the name of a toy and comic book character Rom (Spaceknight). ... Typical hard drives of the mid-1990s. ... In computer networking a media access control address (MAC address) is a unique identifier attached to most forms of networking equipment. ... A BTO vulnerability is a flaw in a copy prevention system that makes a copy of the product where the system has been circumvented Better Than the Original (ie an official copy) in some way. ...


There is also the tool of software blacklisting that is used to enhance certain copy prevention schemes. Software blacklisting is a tool used by manufacturers of software and music on CD and DVD. Essentially the software on the disc will audit the users computer for certain types of virtual CD and CD burning software. ...


Copy prevention for old games

During the 80's and 90's, pre-CD computer games were usually protected with a user-interactive method that demanded the user to have the original package or an item of it, like the manual. Copy protection was activated not at the installation, but every time the game was executed.


Sometimes, the code was needed not at the execution, but in a later point (or points) of the game. This helped the gamer to experience the game (eg. in demonstrations) before buying it, and also made sure that the gamer didn't borrow the manual.


Usually imaginative and creative methods have been employed, in order to be both fun and hard to copy. These include.

  • The most common method ("What is the Ath word on the Bth line of page C?") was often used at the beginning of each game session, but for abovementioned reasons it was abandoned.
  • Manual containing information and hints vital to the completion of the game, like answers to riddles (Conquests of Camelot, King's Quest 6), recipes of spells (King's Quest 3), maze guides etc.
  • Some sort of code with symbols, not existing on the keyboard or the ASCII code. This code was arranged in a grid, and was needed to be entered via a virtual keyboard at the request "What is the code at line X row Y?". These tables were printed in dark paper (Maniac Mansion), or were visible only through a red transparent layer (Indiana Jones and the Last Crusade), so that it was impossible to photocopy.
  • Monkey Island offered one of the most imaginative protection keys: a rotating wheel with halves of pirate's faces. The game showed a face composed of two different parts and asked when this pirate was hanged on a certain island. The player then had to match the faces on the wheel, and enter the year number that appeared on the island-respective hole.
  • Superior Soccer had no outward signs of copy protection, but if it decided it was illegally copied, it would make the soccer ball in the game invisible, thus making it impossible to play the game.
  • Not exactly a protection, but the game companies used to offer goodies with the package, like funny manuals, posters, or fictional documentation concerning the game (eg. the Grail Diary for Indiana Jones or a police cadet notebook with Police Quest) in order to convince the gamers to buy the package.

Conquests of Camelot (full official title: Conquests of Camelot: King Arthur, Quest for the Grail) is a graphic adventure game released in 1989 by Sierra. ... Kings Quest VI is universally known as the high point of the series for its in-depth plot, its landmark 3D graphic introduction movie, and its great voice acting, with actor Robby Benson providing the voice for Alexander, the games protagonist. ... Story In Kings Quest III, the game has moved away from Daventry and King Graham to the land of Llewdor, where a boy named Gwydion is being kept by the wicked magician Manannan. ... There are 95 printable ASCII characters, numbered 32 to 126. ... Maniac Mansion is a graphical adventure game originally released in 1987 by LucasArts. ... Indiana Jones and the Last Crusade is a 1989 movie directed by Steven Spielberg and starring Harrison Ford, Sean Connery, Denholm Elliott, Julian Glover, Alison Doody, River Phoenix and John Rhys-Davies. ... The Secret of Monkey Island, CD version. ... A football, when used in the singular, is a ball used to play one of the sports known as football. ... Police Quest is a series of computer games produced and published by Sierra On-Line between 1987 and 1993. ...

Copy prevention for audio CDs

Starting in 2000, record publishers started to sell CDs with various copy prevention schemes. Most of these are playback restrictions that aim to make the CD unusable in devices that can also be conveniently used for duplicating (e.g., CD-ROM drives in computers), leaving only dedicated audio CD players for playback. This does not, however, prevent such a CD from being copied via analogue connections, which has led critics to question the usefulness of such schemes. 2000 is a leap year starting on Saturday of the Gregorian calendar. ...


This is achieved by assuming certain feature levels in the drives: The CD Digital Audio is the oldest CD standard and forms the basic feature set beyond which dedicated audio players need no knowledge. CD-ROM drives additionally need to support mixed mode CDs (combined audio and data tracks) and multisession CDs (multiple data recordings each superseding and incorporating data of the previous session). Rainbow Books: Red Book (CD Digital Audio), Yellow Book (CD-ROM and CD-ROM XA), Orange Book (CD_R and CD-RW), White Book (Video CD), Blue Book (Enhanced Music CD, CD+G and CD-Plus), Beige Book (Photo CD), Green Book (CD-i). ... The CD-ROM (an abbreviation for Compact Disc Read-Only Memory (ROM)) is a non-volatile optical data storage medium using the same physical format as audio compact discs, readable by a computer with a CD-ROM drive. ...


The play preventions in use intentionally deviate from the standards and intentionally include malformed multisession data or similar with the purpose of confusing the CD-ROM drives to prevent correct function. Simple dedicated audio CD players would not be affected by the malformed data since these are for features they don't support (for example, an audio player will not even look for a second session containing the copy prevention data).


In practice, results vary wildly. CD-ROM drives may be able to correct the malformed data and still play them to an extent that depends on the make and version of the drive. On the other hand, some audio players may be built around drives with more than the basic intelligence required for audio playback. Especially car radios with CD playback, portable CD players, CD players with additional support for data CDs containing MP3 files and DVD players are likely to be problematic. This article needs to be cleaned up to conform to a higher standard of quality. ...


The deviation from the Red Book standard that defines audio CDs required the publishers of CDs produced in such a manner to refrain from using the official CDDA logo on the discs or the cases. The logo is a trademark owned by Philips and Sony and licensed to identify compliant audio discs only. To prevent dissatisfied customers from returning CDs which were misrepresented as compliant audio CDs, such CDs also started to carry prominent notices on their covers. The CDDA trademark Red Book is the standard for audio CDs (Compact Disc Digital Audio system, or CDDA). ... A trademark (Commonwealth English: trade mark)[1] is a distinctive sign of some kind which is used by a business to identify itself and its products and services to consumers, and to set the business and its products or services apart from those of other businesses. ... Koninklijke Philips Electronics N.V. (Royal Dutch Philips Electronics Ltd. ...


Examples of copy prevention schemes are Cactus Data Shield and Copy control. Copy control is the name of a compact disc copy-protection system used on recent EMI CD releases in some regions. ...


Copy prevention in recent digital media

More recently, publishers of music and movies in digital form have turned to encryption to make copying more difficult. CSS, which is used on DVDs, is a particularly famous example of this. It is a form of copy prevention that uses 40-bit encryption. Copies will not be playable since they will be missing the key, which is not writable on DVD-R or DVD-RW discs. With this technique, the work is encrypted using a key known only to authorized players, which allow only "legitimate" uses of the work (usually restricted forms of playback, but no conversion or modification). The Digital Millennium Copyright Act provides a legal protection for this in the US, making it illegal to distribute unauthorized players—which was supposed to eliminate the possibility of building a DVD copier. However, CSS and other such software-based solutions have been reverse engineered (DeCSS), providing access to the encryption keys and methods. The cat-and-mouse struggle continues. In cryptography, encryption is the process of obscuring information to make it unreadable without special knowledge. ... Content-Scrambling System (CSS) is an encryption system used on some DVDs. ... 40-bit encryption is a key size for symmetric encryption representing a low-level of security where the key is forty bits in length (five bytes). ... The Digital Millennium Copyright Act (DMCA) is a controversial United States copyright law. ... Reverse engineering (RE) is the process of taking something (a device, an electrical component, a software program, etc. ... DeCSS is a computer program capable of decrypting content on a DVD video disc encrypted using the Content Scrambling System (CSS). ...


In the future, software cracking may become more difficult to perform with the release of the Fritz-chip in combination with certain software, like Nexus in the next major operating system from Microsoft, code-named Longhorn. Software cracking is the modification of software to remove encoded copy prevention. ... The Fritz-chip is a nickname for the hardware component of a software-execution monitoring system. ... The term Nexus (Latin origin) may mean: a place of being connected, something that connects two objects in a group, a connection between two things. ... In computing, an operating system (OS) is the system software responsible for the direct control and management of hardware and basic system operations. ... Microsoft Corporation, (NASDAQ: MSFT) headquartered in Redmond, Washington, USA, was founded in 1975 by Bill Gates and Paul Allen. ... Longhorn is Microsofts codename (for a full list see Microsoft codenames) for the next version of its Windows operating system, to follow on from Windows XP SP3 [1] and Windows Server 2003. ...


See also

Digital Rights Management (DRM)1 is an umbrella term referring to any of several technical methods used to control or restrict the use of digital media content on electronic devices with such technologies installed. ... A broadcast flag is a set of status bits (or flags) sent in the data stream of a digital television program that indicates whether or not it can be recorded, or if there are any restrictions on recorded content. ... SafeDisc is a CD/DVD copy protection solution by Macrovision Corporation. ... StarForce is a software copy prevention brand by the Russian developer Protection Technology. ... SecuROM is a CD/DVD copy protection solution, most often used for Computer games, by Sony DADC. SecuROM aims to resist home media duplication devices, professional duplicators and reverse engineering attempts. ... PRO-Tectorâ„¢ technology is a Software Copy Protection product from Nalpeiron. ...

Shareware solutions

  • PELock

External links

  • Evaluating New Copy-Prevention Techniques for Audio CDs
  • Loss of confidential proprietary information cost the average business $42,600 in 2004
  • The real deal of copy protections

  Results from FactBites:
 
Software cracking - Wikipedia, the free encyclopedia (986 words)
The distribution and use of cracked copies is illegal in almost every developed country.
A company can also break the copy preventions of programs that they have legally purchased but that are licensed to particular hardware, so that there is no risk of downtime due to hardware failure (and, of course, no need to restrict oneself to running the software on bought hardware only).
Breaking a new copy protection scheme as quickly as possible was often regarded as an opportunity to demonstrate one's technical superiority rather than a possibility of money-making.
  More results at FactBites »

 
 

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